This series of two related conferences is proposed in an attempt to define the major research tasks facing ECT investigators at this time. This proposal is a logical sequel of two prior NIMH-sponsored conferences on ECT during the past decade: "Psychobiology of ECT" (1972) and "ECT: Efficacy and Impact" (1978). The present proposal sets forth a series of interrelated research questions which need to be addressed by the conference participants: 1) What methods can be developed to optimize the selection of ECT pharmacotherapy for patients with major mental illnesses? What are the relative indications, results and long-term effects of ECT and drugs? What is the relative response of clinical subtypes of depression to these methods? What are the clinical and laboratory predictors? What is their relative cost-effectiveness? What are their long-term effects? 2) What is the optimal technique for administering ECT? What are the relative effects of current and electrode placement on behavioral and cortical functioning? What is their interaction? 3) What is the mode of action of ECT? What are the critical neurohumoral and neuroendocrine parameters of treatment? What are the effects on hemispheric functioning? Participants will include Dr. Paula Clayton (clinical assessment, depression research), Dr. Jan Fawcett (neurohumoral studies), Dr. Max Fink (EEG, behavioral studies), Dr. Bernard Carroll (neuroendocrine studies), Dr. Joseph Fleiss (research design), Dr. Michel Mandel (drug therapy and ECT), Dr. Richard Weiner (instrumentation) and others. The questions will be addressed during two two-and-a-half day conferences with the purpose of producing a monograph detailing recommendations for specific projects and their designs.